DISCOVER Magazine #7

The relevance of the scientific research behind Damen’s InvaSave

Published in category: Harbour & Terminal


Reporting the results

Dr. Diana Slijkerman
Researcher at Wageningen Marine Research
in Den Helder, the Netherlands

In developing its award-winning and IMO Type approved InvaSave system, Damen commissioned Wageningen Marine Research to perform an ecological baseline monitoring study looking for marine species in Groningen Seaports to determine the ecological case for such a mobile ballast water treatment system. The results show the ecological significance, as well as the economic motivations, for port-based ballast water management systems (BWMS).

InvaSave received IMO type approval in March of this year. As the IMO Ballast Water Management Convention comes into effect in September 2017, ship owners and operators will be able to take full advantage of this award-winning technology. The InvaSave system has been designed chiefly for use in ports and harbours, to treat water from inbound as well as outbound vessels. The entire system is housed in a standard container, which allows for all-important mobility and flexibility of operations.

The moment of IMO approval, however, has been preceded by a period of committed and focused research and development – both in-house and in collaboration with external partners. To this end, Damen worked closely with Groningen Seaports and the Dutch Waddenfonds, to develop a test case for the viability of such a ballast water treatment product. The fact that Groningen Seaports is located in the UNESCO Heritage Site of the Dutch Wadden Sea only supplemented the ecological significance of a partnership. A crucial part of this product development process involved the commissioning of independent scientific research institute Wageningen Marine Research to investigate the levels of existing exotic species.

Independent research

Wageningen Marine Research conducted research in the two ports that make up Groningen Seaports. “Our research, therefore, involved the saline waters in Eemshaven in addition to the more brackish conditions of Delfzijl,” says Dr Diana Slijkerman from Wageningen Marine Research, referring to the samples taken from the water column, sediment and variety of hard substates. “We took 174 samples in Delfzijl, and 87 in Eemshaven using a variety of techniques. Taxonomic determination found 54 exotic species, meaning that one in five species originate from elsewhere. It’s mainly algae, but also molluscs and crabs, for example. DNA sequencing revealed even more species present which the classical methods could not identify. In addition, three untreated ballast waters were screened too, of which a total of six species were found that were not known for the harbours of Groningen, nor for the Wadden Sea. Of course, different species have different affinities. Most species were found on the hard substrates and water.”


A commercial impact

“We have observed exotic species originating from all over the world,” Dr Slijkerman continues. “But there were a number of prominent examples and ‘known’ exotics for the area. For example, a large number of species that we found originate in the Pacific. Australian barnacles, for instance. They do well in harbour environments and are highly tolerant of changes in temperature and salinity. They compete with native barnacle species for space, and are able to settle at higher levels of the shore as well as deeper into subtidal levels than the native species. An increase of fouling at other places than before is the result.”

The sea walnut, Mnemiopsis leidyi, which established itself about a decade ago, is another example. It arrived from the US via the Black Sea, where it has outcompeted the native anchovy population and decimated the local fishing industry. Thus, a small exotic can have a major economic impact.”

“As said, six ’new’ exotic species in the untreated ballast water were found in this study. Some of these, such as a tube forming worm and another barnacle, prefer warmer conditions, and might have the potential to establish themselves nearby or in cooling water discharge pipes in the harbours. It will be no surprise if they will be found there in upcoming monitoring studies.”

Meeting the challenge

Looking at the results, it’s clear that the economic significance of invasive marine species on local ecosystems takes an equal weight as the ecological impact. In the wider, global perspective, with the shipping industry identified as a critical pathway for species invasions, and maritime trade expected to continue its trajectory of growth, the implementation of the IMO Ballast Water Management Convention is expected to reduce such invasion events.


Damen’s contribution – in offering ports and harbours a single-pass ballast water treatment system that is IMO approved – is a clear response to this particular industry-wide challenge. Having successfully passed fresh, brackish and marine water testing, even with the high sediment levels of turbid coastal waters, its credentials are proven. InvaSave uses mechanical filtration and ultraviolet radiation to meet, and often surpass, IMO D-2 standards to remove and eradicate alien species. This information will be invaluable to ship owners in the run up to September’s implementation.

back to top